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Learning Objectives: Identify how to improve your Power Usage Effectiveness immediately Design an efficient airflow system in a data center and apply to your own facilities Measure and verify the savings achieved in efficient data centers Identify ASHRAE TC 9.9 and its effect on the ecosystem of the data center

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Background Defining the terms: Data center – The room (regardless of size, age, how anyone feels about it, the budget that you have [or had] to build or maintain it, or how reliable it is / is not) that houses your computing equipment.

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Background Defining the terms: Data center Computing equipment PUE – Power Usage Effectiveness. Taking the total facility power (feeding your data center) and dividing by your IT load (UPS load will get you close) will give you your PUE. This PUE number will be greater than 1 (hopefully less than 3) and provides a uniform way of calculating how much power is going to your IT load vs. how much power you are consuming to accomplish your compute (the tax). A PUE of 2 is typical in a legacy center, while a PUE of 1.5 is typical for a new data center build (many are now becoming very aggressive i.e. 1.1 and 1.2). Courtesy of a very sad data center experience

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Background Defining the terms: Data center Computing equipment PUE A tax – Something you pay because you are forced to or because you are not aware of it.

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Background Defining the terms: Data center Computing equipment PUE A tax ASHRAE TC 9.9 – The American Society of Heating, Refrigeration, and Air Conditioning Engineers Technical Committee 9.9 brought together many hardware manufacturers, locked them in a room, and came up with the latest Thermal Guidelines for Data Centers. This is a GUIDELINE NOT A STANDARD. – Your equipment warrantee is provided by your equipment manufacturer and ultimately this is who gets to decide if you are or are not compliant with housing the equipment in a proper environment. Examples: power quality; temperature and humidity controls; particulate type; and size. – In the end data wins…he or she with the most information is likely going to be the person who controls how, when, who, where, and why.

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Background Defining the terms: Data center Computing equipment PUE A tax ASHRAE TC 9.9 Reliability Efficiency – An aggressive pursuit (and an exhausting effort after achieving the appropriate levels of redundancy) to achieve maximum throughput with minimal restriction and waste. – This starts with doing the best you can with what you have, but working intently and diligently to make it better. – Please note that reliability is and must be first. – Walnuts can be opened with steamrollers, but they dont need to be and the result isnt pretty.

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Airflow - A Systems Approach Cause:Meaningful metrics are needed for the data center. Effect:PUE and CUE are now metrics the industry is accepting as standard and yet these are not universally understood or defined. Cause:Delivery systems were developed around outdated guidelines. Effect:Dramatic overcooling of IT equipment! ASHRAE TC 9.9 published new thermal guideline for data centers (~78.6˚F at the intake of compute equipment). Cause: Airflow delivery systems are generally unbalanced and full of air-mixing opportunities. Effect:Typical delivery systems have >50% bypass airflow.

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Airflow - A Systems Approach It all starts with Organization Distribution It falls apart with Poor communication Bad strategy

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Discover Your PUE Calculate how much you are spending now on the system and each part that creates the total. Your CRAC/CRAH efficiency Start with the intake temperature of your server, network & storage equipment. Then calculate the efficiency of your CRAC/CRAH units – (CFM * delta temperature) *.9 = BTUs of accomplished cooling. The path for your airflow Supply path – Supply panels – Aisle layout (hot/cold) – Opportunity for recirculation Return path – What is the path of least resistance?

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Backward-curved blades use blades that curve against the direction of the fan wheel's rotation. The blades are single thickness with 9 to 16 blades inclined away from the direction of rotation. Air leaves the impeller at a velocity less than its tip speed. Relatively deep blades provide efficient expansion with the blade passages. The backward curvature mimics that of an airfoil cross section and provides good operating efficiency with relatively economical construction techniques. Backward-curved fans are much more energy efficient than forward curved fans. The EC Fan design moves the air in more of a straight line. Forward-curved blades use blades that curve in the direction of the fan wheel's rotation. It has 24 to 64 shallow blades with both the heel and tip curved forward. Air leaves the impeller at velocities greater than the impeller tip speed. Tip speed and primary energy transferred to the air is the result of high impeller velocities and operating most efficiently at lowest speed.